This invention relates to an IC memory card having semiconductor data storage elements and also to a mating connector provided to a host device (hereinafter referred to as host device connector). More particularly, this invention relates to a connecting system of the IC memory card and the host device connector.
Generally, an IC memory card has semiconductor data storage elements therein in the form of a card, and is widely used as an external storage for a host device such as a personal computer and POS terminal.
FIG. 15 is a perspective view showing a conventional IC memory card. As shown in FIG. 15, the IC memory card 8 comprises a frame 8a made for example of a resin, and two metal panels 8b having substantially rectangular shape and attached to the frame 8a from upper and lower directions. The metal panels 8b are attached to the frame 8a at the periphery portions of inner surfaces thereof. Elements such as semiconductor data storage elements (not shown) are mounted within the IC memory card. As shown in FIG. 15, a connector 1 is provided on one side wall of a shorter side of the IC memory card 8, and a double line of connector sockets 2 are arranged in a longitudinal direction with tens per one line. Each of the socket contacts 2 is formed in the shape of hole perpendicular to the end surface 1a of the connector 1, and terminals (not shown) electrically connected to semiconductor data storage elements packaged in the IC memory card 8 are formed within the socket contacts 2. As shown in FIG. 15, upside-down preventing grooves 3 which are upside-down preventing-means for preventing the IC memory card 8 from being inserted upside down into a host device connector are provided at both ends of the connector 1 in the form of grooves extending along the longer side of the IC memory card 8. The upside-down preventing grooves 3 have different shapes for preventing the upside-down insertion of the IC memory card.
FIG. 16 is a front view of a host device connector for receiving the IC memory card 8 shown in FIG. 15. FIG. 17 is a sectional view of the host device connector taken along the lines 17--17 in FIG. 16. As shown in FIGS. 16 and 17, the host device connector comprises a connector face 4 having a substantially rectangular shape and a frame-like connector guide 7 provided along the overall outer periphery of the connector face 4. Contact pins 5, which are terminals electrically connected to the inner system of the host device, project from the connector face 4 in the same arrangement as that of the socket contacts 2 so as to correspond to the socket contacts 2 provided in the connector 1 of the IC memory card 8. In the host device connector, upside-down preventing keys 6 are provided along the inner wall of the connector guide 7 perpendicularly to the connector face 4 so as to correspond to the upside-down preventing grooves 3, which is upside-down preventing means of the IC memory card 8. For attachment, the connector 1 of the IC memory card 8 is inserted in the host device connector. However, only when the IC memory card 8 is inserted in a correct orientation are the upside-down preventing keys 6 engaged with the upside-down preventing grooves 3 of the IC memory card 8 to complete attachment. In the IC memory card 8 and the host device connector constructed as described above, the connector 1 provided on the shorter side of the IC memory card 8 is inserted into the host device connector through an IC memory card insertion hole, the socket contacts 2 arranged in the connector 1 of the IC memory card 8 are fitted to the contact pins 5 provided on the host device connector to make contact electrically, whereby the electrical connection between the IC memory card and the host device is obtained. According to the guideline published by Japan Electronic Industry Development Association, the contact pitch and number of terminals of the socket contacts 2 are, for a contact pitch of 1.27 mm, 68 terminals (16 bit data bus) or 1.0 mm for 88 terminals (36 bit data bus) in an IC memory card of standard dimensions (width L 54.0 mm.times.length D 85.6 mm.times.thickness T 3.3 mm). As described above, the upside-down preventing grooves 3 and the upside-down preventing keys 6 are provided on the IC memory card and the host device respectively so that the upside-down preventing grooves 3 are engaged with the upside-down preventing keys 6 only when the IC memory card is inserted into the host device in the correct orientation. Accordingly, electrically wrong operation and breakage of the IC memory card 8 due to the upside-down insertion thereof can be prevented and mechanical breakage of contact pins 5 of the host device due to the insertion of the IC memory card 8 in a wrong orientation, i.e. from other side of the IC memory card where no connector is provided can also be prevented.
Recently, with the development of small-sized portable equipment, a half-sized IC memory card (54.0 mm.times.43.0 mm) has been developed. And, an IC memory card having almost square shape (54.0 mm.times.50.0 mm) larger than the half sized one has also been produced.
The connector 1 is provided on the shorter side of the IC memory card 8 as described above. In order to produce an IC memory card which needs more than 88 terminals, such as an IC memory card having a 64 bit data bus, in an IC memory card having standard dimensions, a connector having socket contacts 2 with a contact pitch narrower than 1 mm should be used. In this case, the dimensional errors occuring in the course of manufacturing accumulate even if they are very small errors, thereby greatly influencing the quality of the IC memory card. Therefore, it is necessary to produce such an IC memory card with very high accuracy. The production is very difficult in view of techniques and cost.
And, when the inner diameter of the socket contacts 2 is reduced and the contact pins 5 are made thinner to increase the number of terminals of the connector, the strength of the contact pins 5 is weakened, so that the contact pins 5 may happen to be undesirably bent and mechanically broken. Although the contact pins 5 are mounted on the connector face 4 made of resin by pressure insertion during manufacturing process, the thinner contact pins 5 can not be subjected to pressure insertion.
Further, when a half-sized IC memory card or an IC memory card having an almost square shape larger than the half sized one, which are described above, is inserted into the conventional host device connector of standard dimensions as shown in FIG. 16 in a wrong orientation rotated 90.degree. from the correct direction, the card is undesirably inserted deeper into the host device connector without being obstructed by the upside-down preventing keys 6 provided on both ends of the host device connector because the width thereof is considerably smaller than that of the host device connector. By this, the contact pins 5 provided in the host device connector may be sometimes damaged, resulting in poor electrical reliability.